Hot ice could have seeded life on Earth

作者：籍军豇 发布时间：2019-03-04 03:15:06

By John Wenz JUST add salt to a new form of ice and we may have the recipe for the primordial soup. Such exotic “hot” ice could also have shaped the geology of our solar system. Ice VII has completely different properties from regular ice. It only forms under intense pressure, and is dense enough to sink in water. Outside of the lab it exists mostly in the deepest layers of Neptune and Uranus, and perhaps also on icy moons like Europa and Ganymede. Arianna Gleason at Los Alamos National Laboratory and Stanford University and her team used a laser to compress water between two sheets of quartz. Next, they placed the water next to a diamond, then fired the laser at the diamond. This recreated the effect of a collision between a comet and a large body like a planet and formed the ice (Physical Review Letters, doi.org/b9q9). “That diamond immediately turns into a plasma and that goes off like a rocket,” Gleason says. “It blows off this shock wave in the opposite direction.” Ice VII formed by this impact could have forever altered the chemistry and geology of moons and planets of the outer solar system, even though it only lasts for nanoseconds before reverting to less exotic ice or water. This form of ice may have changed the strength and composition of surface materials as they separated and created strata within ice crater layers. Shock waves induced by ice VII may also explain why some impact craters have several ridges. And that’s not all. If you factor in salts, a comet slamming into an icy body could create something like the prebiotic soup that led to life on Earth — and that could exist on Europa, Titan or Enceladus. Unlike the panspermia scenarios, where a comet carries biotic material to a lifeless planet, it could instead be the catalyst that creates ice VII,